Does anyone know how to write a formula that will lookup a value and
return the next largest value?

For an example:

A B
1 100 120
2 200
3 300
4 400


I know the formula to return the value that's less than the value I am
looking up.
This is what I use =VLOOKUP(B1, A2:A4, 1, TRUE)
returns 100

How do I get it to return 200? Since 120 is between 100 and 200.

Any help is greatly appreciated!